During the last years, and in the area of household appliances, the international community has increasingly become more conscious of environmental protection. Specifically, it is required that household appliances use less water if water is used, less gas if gas is used, and less energy, which translates into less electricity. Therefore, there exists a need for household appliances to be more energy efficient. In 2008, the European Community applied to the Escobilan for a study on the impact of household appliances on the environment, including clothes dryers. In the same year, the DOE in the United States began to develop a regulatory standard for energy efficiency of clothes dryers, which shall become effective as of Jan. 1, 2015. Thus, it is imminent that household appliances, especially dryers, reduce their energy and gas use, to comply with the future standards and to be more energy efficient.
US publication number 2006086000 makes known a dryer and a method to control the same, where an alert is generated to inform the operator that the dryer is operating abnormally and even if there exists a malfunction in an electric interrupter provided to prevent overheating of a heater in the dryer when the dryer is operating abnormally, the malfunction is prevented from causing additional risk. The heater includes a dryer, an exit duct, an electric interrupter and a control. The heater is provided in order to heat the air. The hot air flows through the exit duct. The interrupter shuts off to deactivate the heater when the heater temperature is outside of a predetermined temperature range. If the interrupter shuts off a certain number of predetermined times or more during the operation of the heater, the control determines that the air flow is abnormal and deactivates the heater.
Japanese publication number 10043499 makes known that when a cycle is selected, until an exit temperature, which is detected by an exit temperature detector which is placed near the drum's air exit, reaches a high limit temperature, two out of the three heaters are turned on and the temperature is slowly raised during a period. When the exit temperature reaches the high temperature limit, only one heater is turned on and the heating is suppressed. Thus, the exit temperature is slowly lowered for a period of time. When the exit temperature is lowered by 4° C. relative to the high temperature limit, both heaters are turned on again and the temperature rises again for a period of time. By turning on part of the heaters even during the time of lowering the temperature in such a way, the range of fluctuation of the temperature is decreased and damage to the textiles is reduced.
Japanese publication number 10043498 makes known that when a substratum temperature is lesser than the reference temperature, until the exit temperature, detected by the exit temperature detector placed close to the drum's air exit, reaches the high limit temperature TH, the three heating pieces are turned on and the temperature is raised for a period of time. When the exit temperature reaches temperature TH, two heaters are on and one is shut off. Thus the exit temperature is gently lowered for a period of time. When the exit temperature is lowered by 1° C. relative to TH, the three heaters are turned on again for a period of time. When the temperature increase continues despite a heater being turned off, all the heaters are turned off when the temperature reaches 4° C. higher than the TH for a period of time. By means of such control, the temperature fluctuation range is decreased and the damage to textiles is reduced.
Japanese publication number 07289798 makes known that during the heating process a microcomputer electrifies the heaters to heat the air transmitted, giving the motor the energy to rotate the drum which rotates a fan which stirs air, and the drying operation is completed, when the temperature difference in the exit temperature detector and the surrounding temperature detector reach the predetermined value. In this instance, when the surrounding temperature is lesser than the predetermined temperature, while the exit temperature is higher than the predetermined temperature only one of the heaters is electrified. When the exit temperature is lower than the prescribed temperature, both heaters must be electrified. Additionally, when the surrounding temperature is lower than the predetermined temperature, while the surrounding temperature is higher than the upper limit, the electricity must be suppressed to both heaters.
U.S. Pat. No. 6,199,300 makes known a method and apparatus to control the heat entrance to a dryer, where the initial heat entrance to the load of clothes is placed on the highest power until a first predetermined temperature or time condition take place. Afterwards, the heat is reduced to reduce energy consumption, while moisture is effectively removed from the clothes load. When the moisture content of the clothes load falls below a predetermined quantity, the complete heat entrance is applied to remove the remaining moisture from the clothes load.
U.S. Pat. No. 5,291,667 makes known a control system for a dryer with a microprocessor which monitors the entrance air temperature and the exiting air temperature. If the entrance temperature exceeds a high value limit a predetermined number of times, an air blocking indicator is activated. The degrees of dryness are measured by the number of times that the entrance temperature has fallen below the threshold value while the heater is turned off because the exit temperature has exceeded the desired value. A drying time is calculated and displayed for the user based on a linear function and exit temperatures measured at the beginning of the cycle and again a short time afterwards.
U.S. Pat. No. 7,444,762 makes known a clothes dryer which has a system for regulating the entering air temperature. The system includes a first detector placed in the dryer's entrance and includes a timer and thermostat, a heat source found in a heating box, adjacent to the first detector and a second detector found at the dryer's exit. The thermostat measures the dryer's entering air temperature and cooperates with the control to prevent the thermostat from reaching its limit temperature and turns off the heat source. Thus, the damage due to excessive air temperatures in the dryer is avoided.
Japanese publication number 03109100 makes known a first temperature detector found in an air discharge part. The air in a drum is suctioned through the filter flow through an exit in the drum and enters the front part of the fan. Afterwards, the air flows through the duct towards a heater, where it is heated by all the heating units of the heater. Thus, the heated air is discharged towards the drum for circulation. On the other hand, the air outside of the dryer is suctioned towards the back part of the fan through an entry point formed in the dryer's back plate and discharged through an air discharger also formed in the back plate. When the first temperature detector, which is placed close to the air discharger, sends a temperature detection signal indicating a higher value than that which was predetermined, initially, the energy supply to the heating unit ceases to decrease the quantity of heat to be generated in one step.
Other documents in the area are US publication number 2003/097764, EP number 0 965 806, JP 04200500, JP 1064700, U.S. Pat. No. 4,485,566 and U.S. Pat. No. 4,267,643.
None of the documents in previous art make known a method to create a household appliance energy efficient, specifically a dryer. Specifically, previous art does not make known a cycle which offers a savings in a dryer's energy consumption, in comparison to that of traditional cycles.
Thus, a need exists for an efficient energy or gas control for drying, so that drying may be benefitted from the discovery of an efficient moisture reduction in constant cycles with less drying energy or maximum inner temperature.